1. Field of the Invention
The present invention relates generally to the field of pipe and fitting connections, and more particularly, is directed to an improved bell and spigot joint including an integral, exterior, reinforcing ring for strengthening the bell.
2. Discussion of the Prior Art
It is presently the usual practice to extrude plastic pipes in elongate, cylindrical configuration of a desired diameter and wall thickness and then to cut the extruded product into individual lengths of convenient size suitable for handling, shipping and installing, for example, ten foot lengths or twenty foot lengths. Each length of pipe is enlarged or "belled" at one end sufficiently to join the next adjacent pipe section by receiving therewithin the unenlarged or "spigot" end of the adjacent length of pipe. The inside diameter of the bell is formed sufficiently large to receive the spigot end of the next section of pipe with sufficient clearance to allow the application of packing, caulking, gaskets or other devices which have been designed and used to prevent leakage at the pipe joints when a plurality of pipe lengths are joined to form a pipe line. Depending upon the intended pressure of the fluid being conveyed, and other design parameters, the seal within the joint between adjacent lengths of pipe will be required to be more or less sophisticated.
Similarly, fittings have been fabricated for compatible use within the piping systems to accommodate various design characteristics, such as ells, wyes, tees and the like. Such fittings have been designed with one or more bells or sockets at the fitting extremities, depending upon the intended use and purpose of each fitting.
Prior workers in the art have found that the weakest part of the piping system is usually the bell or socket portion, either in a length of pipe or in a fitting. Frequently, when a pipe joint is being made up in the field, the parts are not precisely positioned in axial alignment by the workers, thereby placing additional stress upon the bell as the spigot of the part to be connected is inserted. In other instances, the spigot end of the pipe to be joined together with the associated packing or sealing materials may be too large for the bell or socket, thereby also placing large stresses on the bell or socket. In extreme conditions, the misalignment or oversize of the parts can result in the splitting of the bell, thereby requiring immediate repair or replacement of the part in order to maintain the integrity of the system. Sometimes, the damage to the bell is not noticed at the time of installation and the damaged part is covered and hidden from view. Under such circumstances, the costs of repair will be greatly increased due to the extra time and equipment required to first locate the damage and then to excavate to expose the faulty part.